At present, a joint wiring terminal box is widely used, wherein screws and metal sheets are connected in a slip-on manner. To ensure a current circuit to stay in a short-circuit condition (not short-circuited), relevant regulation operations should be strictly implemented, which has a high requirement for the operators, and even in this case, misoperations and wiring mistakes still occur. Furthermore, since metallic terminals are exposed, it is required to manually switch the metallic terminals to change the wirings of the current secondary circuit or to short-circuit the secondary current, which has a large potential safety hazard, and many safety accidents happened in the past.
In the electrical system, as a legal measurement meter, an electric energy meter used for trade settlement has to be periodically calibrated. In a conventional calibration method, current or voltage metallic connecting pieces at an electric energy meter panel, where a conventional joint wiring terminal box is mounted, are switched or connected in parallel to perform an error comparison under real load in the same measurement secondary circuit between a standard meter, having an accuracy standard higher than that of the electric energy meter to be calibrated, and the electric energy meter mounted in the filed. However, during the process of connecting the standard meter into the measurement secondary circuit, situations that causing harm to the human body and damages to equipments may happed, for example, a current secondary circuit being opened or a voltage secondary circuit being short-circuited may be caused when switching the current metallic connecting pieces or picking up voltage signals.
A technical issue to be addressed by those skilled in the art is to provide a wiring device which may not only ensure the operational safety but also improve the work efficiency.